Pivotal joint between an alternating-current electromagnet and its armature.



A. AICHELE. PIVOTAL JOINT BETWEEN AN ALTERNATING CURRENT ELECTROMAGNETAND ITS ARMATURE.

APPLICATION FILED DEC-30.1916- Patented Feb. 5, 1918.:

UNITED STATES PATENT OFFICE.

ALBERT AICHELE, OF-BADEN, SWITZERLAND, ASSIGNOR TOIAKTIENGESELLSCHAFTBROWN BOVERI & CIE., OF BADEN, SWITZERLAND.

' PIVOTAL JOINT BETWEEN AN ALTERNATING-CURREN ELECTROMAGNET AND ITSARMATURB.

Specification of Letters Patent.

Patented Feb. 5. 1918.

Application Med December 30, 1918. Serial No. 139,907.

I To all whom it may concern:

Be it known that I, ALBERT Alex-inns, a

'citizen of the p i s s Republic, residing at No. 10 \Viesenstrasse', inthe town of Baden, in Switzerland, have invented certain new and usefulIm rovements in Pivotal Joints.

Between an lternating-Current Electromagnet and Its Armature, of whichthe following is a specification.

' This invention relates to alternating current electromagnets of the tye wherein the Y armature is 'plvoted to the rame or body of the magnet,and the improvements have for their object to provide an improvedpivotal connection between the alternating current electromagnet and itsarmature in such a case;

In the construction hitherto employed the pivot pin' of the armature hasa slight amount of play in itsbearings which may be due to themanufacture or be the result of wear, and this play causes a buzzingnoise in the operation of the magnet.

This buzzing noise is prevented by the I present invention whichconsists in pressing the pivot pin of the armature firmly against itsbearings in the fixed body of the'magnet .by means of endless elasticdevices placed .mnder tension. By this means the vibration that producesthe buzzing is either entirely prevented or at least is limited to a fewrare occurrences. j I

The simplest way of carrylng this invention into ell'ect is to use anendless elastic 85 band, for instance an endless rubber band 4 or ahelical spring formed into a closed 100 which is looped under tensionaround bot the pivot pin of the armature and a. projection of the bodyof the magnet.

40 An embodiment of this invention is illustrated by way of example inthe accompanying drawings in which Figures 1 and 2 are respectively a.side elevation and a vertical. section of an electromagnet with apivoted armature. I

Fig. 8 shows a detail.

In this'example :a is the body of the electromagnet, and b is thearmature pivoted to it. c are the cheeks of the electromagnet;

they are formed at their lower ends with notches d that serve asbearings for the pivot pin 6 of the armature'b. fare two closed loopseach composed of an endless helical spring. 9 are projections locatedoneon each of the two sides of the magnet body a. The sprin loops f arelooped under tension around tie ends of the pivot pin e andthefp'rojections g, andlthey have thus a con- "stunt-tendency to keepthe pivot pin e well up against its bearings d in the magnet body Inorder to prevent an accidental disengagement of the springs f from.their seats d and g, and also for the purpose of preventing thearmature b from dropping in ca of a spring f breaking when no currentisassing through the magnet, plates h are xed to the projections g bymeansof screws i. These plates k which are shown in'Figs. 2 and 3, areomitted in Fig. 1 for the sake of clea rness. 1

' The improved arrangement has the fadvantage of allowing the armature 5tubev very'easilyrernbved from and replaced ,on

the. magnet a. 'In order to disconnect-the armature from'the magnet itsuiiicient to unscrew the screws 2', remove the plates h and then'slipthe springs f ofl' one or other or both of the parts c andgr Y '1WhatIclaim is: E. 1. In an alternating current electromagnot having anarmature pivoted thereto, the

net, a pivot member on said armature co operating with said bearinginotch to form ,the pivotal connection betweehsaid armature andsaidmagnet, "and an endless elastic member looped arounu's'aid magnetand said pivotmember and having acon'stant tendenc to keep said pivotmember pressed into sai bearing notch. I

3. In an alternating current electromagnet having an armature pivotedthereto, the

combination" of a bearing-notch in said-magnet, a. pro ection on saidmagnet located inword of said bearmgnotch, a pivot member on saidarmature cooperating with said bear:

ing notch to form the pivotal connection between said armature and saidmagnet, and an elastic closed loop composed of a helical spring loopedunder tension around said projection and said pivot member so as to havea constant tendency to press said pivot member in said bearing notch.

4. In an alternating current electromagnet having an armature pivotedthereto, the

combination of a bearing notch in said magnet, a projection on saidmagnet located in ward of said bearing notch, a pivot member on saidarmature cooperating witlr said bearing notch to form the pivotalconnection between said armature and said magnet an elastic closed loopcomposed of a helical spring looped under tension around said projectionand said pivot member so as to have a constant tendency to ress saidpivot member in said bearing'notc and a platelike member formed with ahole for engag-' ALBERT AICHELE.

